Submitted by Nick Vahalik on Thu, 11/05/2009 - 11:35
I've been doing a lot of cleanup of certain modules at the office. Two in particular are heavily used apps that incorporate pre-made default views with screens to add nodes or do information lookups. Part of the problem with this is that although I had a decent URL structure (many paths were aliased), my breadcrumbs were never right. I usually had to override them to make them work the way I wanted to (Drupal 5 on my end):
drupal_set_breadcrumb(array(...))This is a hack! "path.module":http://api.drupal.org/api/drupal/modules--path--path.module/5 is great for aliasing content paths. But stay away from it for stuff in your module. Drupal's "drupal_get_breadcrumb":http://api.drupal.org/api/function/drupal_get_breadcrumb/5 actually calls "menu_get_active_breadcrumb":http://api.drupal.org/api/function/menu_get_active_breadcrumb/5 to figure out what to put in the breadcrumb list. Essentially, this function goes through the url, and looks at each element, gets the title of them if they have the "MENU_VISIBLE_IN_BREADCRUMB":http://api.drupal.org/api/constant/MENU_VISIBLE_IN_BREADCRUMB/5 flag on them. Both "MENU_NORMAL_ITEM":http://api.drupal.org/api/constant/MENU_NORMAL_ITEM/5 and "MENU_ITEM_GROUPING":http://api.drupal.org/api/constant/MENU_ITEM_GROUPING/5 have that flag by default. Basically, if you write your "menu hook":http://api.drupal.org/api/function/hook_menu/5 properly, your breadcrumbs will automatically populate for you without any extra work. The key here is putting this in your menu hook. If you use path.module's "path_set_alias":http://api.drupal.org/api/function/path_set_alias/5 or you add it manually via the interface, it *won't work!* The reason is due to the fact that this is an alias. If you do this, "menu_get_active_breadcrumb":http://api.drupal.org/api/function/menu_get_active_breadcrumb/5 will see the "true" path and not the "aliased" path. For example: Let's say you have a node form that you want to put inside your path somewhere. If you do:
path_set_alias('node/add/claim','agents/claims/create')Your breadcrumb for "agents/claims/create" will show the breadcrumb you will see on "node/add/claim." (probably just "Home") However, if you do this:
$items = array( 'path' => 'agents/claims/create', 'type' => 'callback', 'callback' => 'node_add', 'callback arguments' => array('claim') );Your breadcrumb will display something along of: Home » Agents » Claims Which is exactly what you want! There is *always* a way to make the menu do what you want it to do. This includes using "node_add":http://api.drupal.org/api/function/node_add/5 to put node creation forms where you want them or using "views_view_page":http://drupalcontrib.org/api/function/views_view_page/5 for displaying views. It will make your breadcrumbs work right and make your code cleaner since you won't be putting urls and menu information in your "default views hook":http://drupal.org/node/99568!